Strain, Young's modulus, and structural transition of EuTiO3 thin films probed by micro-mechanical methods

Abstract

EuTiO3 (ETO) is a well-known complex oxide mainly investigated for its magnetic properties and its incipient ferro-electricity. In this work, we demonstrate the realization of suspended micro-mechanical structures, such as cantilevers and micro-bridges, from 100 nm-thick single-crystal epitaxial ETO films deposited on top of SrTiO3(100) substrates. By combining profile analysis and resonance frequency measurements of these devices, we obtain the Young's modulus, strain, and strain gradients of the ETO thin films. Moreover, we investigate the ETO anti-ferro-distorsive transition by temperature-dependent characterizations, which show a non-monotonic and hysteretic mechanical response. Comparison between experimental and literature data allows us to weight the contribution from thermal expansion and softening to the tuning slope, while a full understanding of the origin of such a wide hysteresis is still missing. We also discuss the influence of oxygen vacancies on the reported mechanical properties by comparing stoichiometric and oxygen-deficient samples.

arXiv comment8 pages, 5 figures; 7 Supplementary Material sections

References in corpus (10)

• A general procedure for thermomechanical calibration of nano/micro-mechanical resonators
• Analogies of structural instabilities in EuTiO3 and SrTiO3
• Antiferrodistortive phase transition in EuTiO3
• Giant strain gradient elasticity in SrTiO3 membranes: bending versus stretching
• Effects of oxygen-reducing atmosphere annealing on LaMnO${}_3$ epitaxial thin films
• Selective high frequency mechanical actuation driven by the VO2 electronic instability
• Charge doping and large lattice expansion in oxygen-deficient heteroepitaxial WO3
• Structural and magnetic phase transitions in EuTi1-xNbxO3
• Large tunability of strain in WO3 single-crystal microresonators controlled by exposure to H2 gas
• The role of etching anisotropy in the fabrication of freestanding oxide microstructures on SrTiO3(100), SrTiO3(110), and SrTiO3(111) substrates

Cited by in corpus (2)

• Integration of High-Tc Superconductors with High Q Factor Oxide Mechanical Resonators
• Oxide Membranes from Bulk Micro-Machining of SrTiO${}_3$ substrates